On properties of the conformal circulant matrices

Abstract

In this paper, we introduce and study conformal permutation matrices. In particular, for a permutation ${\pi }_s\in S_n$, we define the corresponding conformal permutation matrix $H_{{\pi }_s}$ and show that its $d-$th power, where $d=n/\gcd (s,n)$, is a diagonal block matrix whose blocks are products of certain matrix blocks $h_i$. We further show that these diagonal blocks share a common subset of eigenvalues and prove that $H_{{\pi }_s}$ is block-diagonalizable. We also introduce the notion of conformal circulant matrix and investigate its eigenvalues. Finally, we establish a necessary and sufficient condition for a rectangular matrix to be conformal circulant.